1. Field of the Invention
This invention relates to a weight lifting device, and in particular to a weight lifting device which can be varied in weight for ease of transport and portability.
2. Description of the Prior Art
Many weight lifting devices have been developed over the years. These include conventional free weights such as bar bells and dumbbells. Conventional bar bells and dumbbells comprise a handle or bar to which weights are attached at opposite ends of the bar. The weights may be disk-shaped iron plates or plastic shells filled with a heavy material, such as sand, concrete or shot. The weights are often removable so that the weight of the bar bell or dumbbell can be adjusted by adding or subtracting the number of weights. While these weight lifting devices are quite good, they are very cumbersome, heavy to ship and cannot be transported from place to place without great effort.
Because of this, lightweight or portable bar bells and dumbbells have been developed which can be easily converted to increase their weight. In their simplest form, these weight lifting devices consist of containers which are attached or joined to a handle or bar. The containers have an opening in which a readily available material, such as water, can be introduced to increase the weight of the device. The material is then emptied from the containers to decrease its weight for portability or transport. This makes the handling of the devices much easier and allows the user to carry them from place to place with less effort. Many different embodiments of weight lifting devices employing fillable containers are known in the prior art. An example of such a device is disclosed in U.S. Pat. 3,756,597 which teaches a weight lifting device having containers mounted on either end of a bar. The containers are filled with water or other material and are provided with indicia or fill lines for determining the level of fluid needed to achieve a desired weight.
The problem with these prior art lifting devices is that in order to vary the weight within the containers, the amount of fluid or substance necessary to provide the appropriate weight may be less than that required to fill the containers. Thus, during movement of the bar bell or dumbbell, the fluid within these containers tends to slosh or move about within the container. This is distracting to the user and interferes with the enjoyment and use of the weight lifting device.
What is needed is a simple weight lifting device having containers which can be filled with a weighting fluid, such as water, so that the free space within the containers is minimized to prevent movement of the fluid within the containers, and which does not require fill lines or other indicia on the containers to determine the appropriate level of fluid for a desired weight.